Math Is Fun Forum

Toast

Real Member

Registered: 2006-10-08

Posts: 1,321

Index Laws Practice

To complete these questions it will be necessary to know the Index Laws:
Law 1:

Law 2:

Law 3:

Law 4:

Law 5:

And the rational index laws:

Also, we define

, where

To prove this:

, but

1: Simplify with positive indices:
a)

b)

c)

d)

e)

2: Simplify with positive indices:
a)

b)

c)

d)

e)

3: Simplify with positive indices:
a)

b)

c)

d)

e)

4: Express as a power of x:
a)

b)

c)

d)

e)

Last edited by Toast (2007-05-07 02:22:15)

nova_angel

Member

Registered: 2007-09-24

Posts: 1

Re: Index Laws Practice

Hey..thats cool...may you post some level 9 or secondary 3(asia) practice to the forum... i need more practise...anyway thank you~~this is kinda cool...

kmlb123

Member

Registered: 2007-12-28

Posts: 1

Re: Index Laws Practice

ahhh...finally something i can understand ty for this stuff and could u upload some other stuff like medium level coordinate geometry (i drag at it)  TY4 THIS

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,410

Re: Index Laws Practice

Hi kmlb123!
Happy to learn that you found this Exercise useful!
I shall post more exercises at Middle School/High School level;
certainly I shall try to post an exercise exclusively on Coordinate Geometry.

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Ash Okas

Member

Registered: 2013-01-07

Posts: 1

Re: Index Laws Practice

Exercise online, good see the stuff, helpful for kids and all, It inspired me to join the lovely forum, evoked my forgotten love for maths

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Index Laws Practice

hi

Some people discover this forum but don't realise there is a huge wealth of excellent math teaching material including exercises at

http://www.mathsisfun.com/

Try it!

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Index Laws Practice

Hi Ash Okas;

Welcome to the forum. Tell us about yourself in "Introductions."

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

noelevans

Member

Registered: 2012-07-20

Posts: 236

Re: Index Laws Practice

Hi Toast!    Nice set of problems!

Here is a variation of law 2 that is easy to use and always ends up with a non-negative exponent.
It takes care of all three cases:  m>n, m=n, m<n.  It is especially nice when the problem involves
negative exponents.

(p is the opposite of the smaller of m and n)  For example recalling that a^0 = 1 we get
( Whether this is true for a=0 has been thoroughly explored in other threads of this forum.)

       m     n          p       a^(m+p)/a^(n+p)

       2      5         -2     a^0 / a^3  = 1/(a^3)
       3     -2          2     a^5 / a^0  =  a^5   
      -5     -3          5     a^0 / a^2  = 1/(a^2)
       4     -7          7     a^11 / a^0 = a^11
       3      3         -3     a^0 / a^0  = 1
      -4     -4          4     a^0 / a^0  = 1

Of course the last two cases here would obviously be 1 from the start.

This law takes care of all cases for positive, negative or zero exponents m and n, leaving the
answer with a non-negative exponent for a in the numerator or denominator as most books
require for the answer.

If p is anything else but -min(m,n) the equality is still true, but it will not be in "simplified" form.

Play around with it a bit and I think you will find it is quite handy and easy to use.

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Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.